Chorea-Acanthocytosis (ChAc)

Overview

What is Chorea-Acanthocytosis?

Chorea-Acanthocytosis (ChAc) is a rare disorder that is characterised by progressive neurodegeneration and red cell acanthocytosis. (Acanthocytos is a red cell phenotype found in various underlying conditions - acanthocytes are pathological red blood cells that resemble many-pointed stars).

ChAc onset is usually between 25 and 45 years of age, although it can develop as early as the first decade or as late as the seventh decade. There is as yet no effective long-term treatment for this disorder. It runs a chronic progressive course and may lead to major disability within a few years. Life expectancy is reduced.

ChAc is characterised by a progressive movement disorder, progressive cognitive and behavioural changes, seizures, and a myopathy resulting in progressive distal muscle wasting and weakness. In addition to classic choreic movements, motor or vocal tics, dystonia, parkinsonism, progressive supranuclear palsy and apraxia of the eyelid opening are observed.

Is Chorea-Acanthocytosis genetic?

Chorea-Acanthocytosis (ChAc) is a single-gene disorder. It is caused by mutations in just one gene, called CHAC, that is found on the chromosome 9. ChAc is an inherited disorder that shows autosomal recessive inheritance, meaning that there is a one in four chance that the brother or sister of an affected individual will also be affected by the disorder.

What are our goals?

In 2001, researchers in the Monaco Group ChAc research team were part of the group that first identified the CHAC gene, which is responsible for ChAc. Since then, the team has identified and characterised three other human genes whose encoded proteins present a high level of similarity to that encoded by CHAC.